The purpose of Mophie's Juice Packs are to give your iPhone that extra boost when its battery is running low. The Mophie Juice Pack Air and its beefier cousin, the Juice Pack Plus for the iPhone 4 are no different, each providing over five hours of additional Internet and talk time over 3G.
Despite initially feeling bulky, we found plenty of reasons to keep either the Air or Plus attached to our iPhone or stored in our messenger bag for those hard partying nights.
Keeping That iPhone Running and Running and Running
Those who use their iPhones around the clock will already know all about Mophie's history with creating external battery pack cases. While some will be turned off by the slightly added heft (you'll grow used to it real quick), the 1500 mAh Air and 2000 mAh Plus batteries pull their weight. On 3G, the Air provides up to six hours of talk time and up to five hours of additional Internet use, while the Plus gets up to eight hours of talk time and seven more hours of Internet. We got roughly the same hours for both voice and data, give or take a few minutes, depending on how we used it.
Form and Functionality
Both the Air and Plus packs charge via an included Micro USB cable and have an LED status indicator and standby/charging switch. We absolutely love the LED indicator — it's just like the one that's on the side of the MacBook family.
A kick-stand is noticeably missing from the Mophie packs, something iKit's NuCharge battery pack case does have. Hopefully, Mophie will consider one for the inevitable iPhone 5 battery pack update.
You'll also notice that your iPhone 4 just barely slides into the Mophie packs. The fitting is so skin-tight that we ended up scuffing the bottom of our iPhone 4's steel band due to constant rubbing of the case's dock connector and the iPhone's 30-pin port. It's not a big issue, but now our pristine iPhone 4's steel band isn't as virginal anymore, and that's a real bummer.
Acoustic Sound Enhancement
At first we were very skeptical about Mophie's preaching that the Air and Plus could actually make watching videos and playing games (not Angry Birds, we turn the sound off on those annoying birds and pigs) clearer. We were wrong, the case's "virtual speaker box" redirects sound from coming out of the bottom of the iPhone 4 to blast it in your face. The end result is that your hand is not muffling the speaker when you're playing a racing game like Need for Speed: Hot Pursuit that requires you to tilt to steer a car. Videos and games end up having more "boom" to them — which definitely made entertainment more engrossing.
Hotspot's Best Friend
With Verizon's iPhone 4 rocking the coveted hotspot feature (up to five devices can use the iPhone 4 as a portable Wi-Fi router) and AT&T slated to get the feature through a firmware update, owners who use this feature will notice battery life decrease more rapidly. For power users, the Plus is going extend your iPhone 4's battery quite a bit. We could write a short novel with seven extra hours!
Overall, at $80 for the Air and $100 for Plus, we'd say the Mophie packs are great investments. The Air is more than sufficient enough for most people's needs. We can't tell you how many times we were out into the twilight hours and when our iPhone 4 ran dry, we popped on a Mophie and continued partying. Nothing sucks more than telling someone you can't text them because your iPhone is dead or at under 10-percent.
Verizon iPhone 4 Compatibility Note:
Sadly, the AT&T Mophie Air and Plus battery packs aren't compatible with the CDMA iPhone 4 (the mute switch on the CDMA iPhone 4 is slightly lower than the one on the GSM iPhone 4). If you want a battery pack for your new Verizon iPhone 4, you can pick up Mophie's just announced CDMA-iPhone 4 compatible Juice Pack Air. No Juice Pack Plus has been announced for the Verizon iPhone 4 yet. Requiring a new Mophie Juice Pack Air definitely sucks for Verizon iPhone 4 switchers, but hey, with the iPhone 5 right around the corner, latecomers to the iPhone 4 party should probably just wait for what is sure to be an iPhone 5 Mophie pack.